Shader: Fix SpirV generation for Swizzle expressions

+ fix OpSampledImage

src/Nazara/Shader/SpirvAstVisitor.cpp

@@ -727,16 +727,17 @@ namespace Nz
 
 	void SpirvAstVisitor::Visit(ShaderAst::SwizzleExpression& node)
 	{
-		const ShaderAst::ExpressionType& targetExprType = GetExpressionType(node);
-		assert(IsPrimitiveType(targetExprType));
-
-		ShaderAst::PrimitiveType targetType = std::get<ShaderAst::PrimitiveType>(targetExprType);
-
 		UInt32 exprResultId = EvaluateExpression(node.expression);
 		UInt32 resultId = m_writer.AllocateResultId();
 
+		const ShaderAst::ExpressionType& targetExprType = GetExpressionType(node);
+
 		if (node.componentCount > 1)
 		{
+			assert(IsVectorType(targetExprType));
+
+			const ShaderAst::VectorType& targetType = std::get<ShaderAst::VectorType>(targetExprType);
+
 			// Swizzling is implemented via SpirvOp::OpVectorShuffle using the same vector twice as operands
 			m_currentBlock->AppendVariadic(SpirvOp::OpVectorShuffle, [&](const auto& appender)
 			{
@@ -751,6 +752,10 @@ namespace Nz
 		}
 		else
 		{
+			assert(IsPrimitiveType(targetExprType));
+
+			ShaderAst::PrimitiveType targetType = std::get<ShaderAst::PrimitiveType>(targetExprType);
+
 			// Extract a single component from the vector
 			assert(node.componentCount == 1);
 

src/Nazara/Shader/SpirvConstantCache.cpp

@@ -546,7 +546,7 @@ namespace Nz
 		auto imageType = Image{
 			{}, //< qualifier
 			{}, //< depth
-			{}, //< sampled
+			true, //< sampled
 			SpirvDim::Dim2D, //< dim
 			SpirvImageFormat::Unknown, //< format
 			BuildType(ShaderAst::PrimitiveType::Float32), //< sampledType
@@ -791,9 +791,9 @@ namespace Nz
 
 				UInt32 sampled;
 				if (arg.sampled.has_value())
-					sampled = (*arg.sampled) ? 1 : 0;
+					sampled = (*arg.sampled) ? 1 : 2; //< Yes/No
 				else
-					sampled = 2;
+					sampled = 0; //< Dunno
 
 				constants.AppendVariadic(SpirvOp::OpTypeImage, [&](const auto& appender)
 				{